Valve control mechanism for internal combustion piston engines



Oct. 30, 1962 A. J. BUCHI 3,060,916

VALVE CONTROL MECHANISM FOR INTERNAL COMBUSTION PISTON ENGINES FiledSept. 21, 1960 2 Sheets-Sheet l Oct. 30, 1962 A. J. BUCHI 3,060,916

VALVE CONTROL MECHANISM FOR INTERNAL COMBUSTION PISTON ENGINES FiledSept. 21, 1960 2 Sheets-Sheet 2 United States Patent D 3,060,916 VALVECONTROL MECHANISM FOR INTERNAL COMBUSTION PISTON ENGINES Alfred JohannBuchi, Archstrasse 2, Winterthur, Switzerland Filed Sept. 21, 1960, Ser.No. 57,446

Claims priority, application Switzerland Sept. 26, 1959 7 Claims. (Cl.123-79) The present invention relates to valve control mechanism forinternal combustion piston engines of the kind having concentric innerand outer valves, the outer valve being guided in the cylinder head andthe inner valve being guided within the outer valve.

According to the invention there is provided valve control mechanism foran engine of the kind described comprising an overhead camshaft, rockerarms operable by cams on said cam shaft for opening the valves, springmeans for closing the valves, a cam on the camshaft and a rocker arm forthe inner valve being arranged in a plane containing the valve axis, andtwo cams on the camshaft and two rocker arms for the outer valve beingspaced symmetrically of the valve axis and extending parallel to the camand rocker arm for the inner valve, said rocker arms being rotatablymounted on a common shaft, an element intermediate the rocker arms andthe outer valve and operatively connected to the actuating stern of theouter valve, said element comprising a cup- -like centre part andextensions parallel to the cam shaft and projecting from the cup-likecentre part, said extensions co-acting with the rocker arms of the outervalve to open the outer valve, and said cup-like centre part co-actingwith said spring means for the outer valve, and a retainer member forthe spring means of the inner valve, said retainer member having atleast two arms and being firmly connected to the actuating stem of theinner valve, the arms on the retainer member being received in slots insaid cup-like centre-part, the arms being reciprocable in said slots.

Specific embodiments of the invention are shown by way of example in theaccompanying drawings whereof:

FIG. 1 is an axial section transversely through the cylinder head of aninternal combustion engine having valve control mechanism according tothe present invention, the control mechanism being shown in its positionin which the inner valve is open,

\FIG. 1a corresponds with FIG. 1 but shows the valve control mechanismin its position in which both the valves are closed.

FIG. 2 is a longitudinal section through a part of the cylinder head andthe control mechanism shown in FIG. 1.

FIG. 3 is a transverse section showing a modification of part of thecontrol mechanism shown in FIGS. 1, la and 2.

FIG. 4 is a longitudinal section corresponding with FIG. 3.

FIG. 5 is a plan view of a part of the control mechanism shown in FIGS.3 and 4.

FIG. 6 is a longitudinal section showing a further modification of partof the control mechanism shown in FIGS. 1, 1a and 2 and,

FIG. 7 is a plan View of FIG. 6.

In FIGS. 1, 1a and 2, Z is the cylinder head and R is a housing for thecylinder head and the control gear. The outer valve V is guided in thecylinder head and V is the inner valve moving concentrically of andinside the outer valve. The valves are opened by an overhead cam shaft'1 with control cams 2 and 3 (FIG. 2) and by means of rocker arms 4pressing on the valve stems or valve spring retainers. The valves areclosed again by the valve springs 6 and 6a for the inner valve and valve3,066,916 Patented Oct. 30, 1962 springs 9 for the outer valve. FIG. 1shows the inner valve V in the open position and the outer valve V inthe closed position. In FIG. 1a, both valves are closed, the inner valvebearing on the outer valve and the outer valve on the cylinder head.Each of the two valves has its control members which can be actuatedindependently of those appertaining to the other valve. The cam shaft 1is driven in known manner through a transmission from the crankshaft.The middle cam lies in a transverse plane of the cylinder head, whichplane extends through the centre line of the valves, the middle camcontrolling the inner valve V The other two cams control outer valve Vand are also provided in a transverse plane of the cylinder head whichis parallel to the cylinder axis. The control cams press on the rockerarms 4 and these can be provided with a device 5 which cancels outlheplay between one rocker arm and the pressure points on the valve rods.The rocker arms 4 are rotatably fixed on the shaft 4b and are sodesigned that they are interchangeable. The restoring means of the innervalve consist of two two-part hair-pin springs 6 and 6a, which act eachvia a stirrup 7 on the one end of a two-armed valve spring retainer 8,8a which may be constructed in the form of a yoke and rigidly attachedto the stem 13 by means of a two part conical member 16. The springretainer 8, 8a has at 8b a track of a width to accommodate horizontalmovement of the stirrup 7.

The springs 6 and 6a are held at the other end on the cylinder head bymeans of a plate 20. The return spring of the outer valve V consists ofa helical spring 9, as shown in FIGS. 1, la and 2. Between the rockerarms 4 for the outer valve and the actuating stem 15 there is disposed apot-shaped engine element 10, which comprises a centre part 10 andextensions 10a projecting from the upper rim of the centre part (FIG.2). The extensions ltla each co-operate with one rocker arm 4 and inknown manner with movable ball sockets 10c and ball pins 411. The baseof this engine element is screwed fast to the hollow stem 15 of theouter valve V The screw connection 15a consists of an internal thread ofone attachment 11 projecting outwardly from the base of the engineelement, and an external thread on the hollow stem 15. The attachment 11is made in one piece with the pot-shaped engine element or is connectedrigidly to the latter. The screw connection 15a is locked by means of ascrew-threaded nut 12. The engine element serves the purpose of aretainer for the spring 9 of the outer valve, it being supported on thecylinder head Z and pressing on the base portion of the element 10 forclosing the outer valve V FIGS. 3 and 4 show a modification of thepot-shaped engine element. In this case, the engine element 16'comprises two separate upper and lower parts 18 and 14 whereof thedownward projection of the lower part 14 is attached to the actuatingstem 15 of the outer valve. A ball joint 19 is provided between theupper cup or potlike part 18 and the lower part 14, and the pot 18 issupported in a spherical surfiace 14a of the lower part 14, which isscrewed fast to the hollow stem 15 or is made in one piece with thestem. The base of the pot 18 is given a suitable spherical form forforming the ball joint 19. With this modification, the outer valve withthe stem 15 and the lower part 14 can be rotated about the stem 13 ofthe inner valve.

FIG. 5 is a plan view showing the relative positions of the membersserving as spring retainers for the outer and inner valves, and of theyoke 8 and the pot-shaped element 10' in the construction according toFIGS. 3 and 4. The yoke arms 8a of the inner valve and the vane-likeextensions we of the pot-shaped element 18 are set at right-angles toone another. Furthermore, the yoke arms 8a extend into the wall of theelement 10' through slots b displaced by 180. Owing to the ball joint.19, the sockets 100! can be'made in one piece with the arms 10c or beconnected fast thereto. In the event of any inaccuracies in the settingof the rocker arms a satisfactory guiding of the stem in the guideway 21without any binding is assured because of the ball joint. The formationof the operative point between the rocker arm and engine element in theform of a ball joint 4a/10d, in conjunction with the ball joint 19,provides for axial power transmission of the control forces transmitted-from the control cams to the valves.

In FIGS. 6 and 7, a helical spring 6 is provided instead of the two-parthair-pin springs 6, 6a with stirrups 7, which spring 6' surrounds thehelical spring 9 and the pot 18 of the element 10' for the outer valve VThe valve spring retainer 8' for the cylindrical spring 6 is three-armedwith arms 8a offset at 120 relatively to one another. These armsco-operate with the cylindrical spring 6 by means of a ring 6". Asdescribed for the two-armed spring retainer in connection with FIG. 4,the three-armed spring retainer 8' is connected fast to the stem 13' ofthe inner valve by means of keys 16. The pot 18 of the element 10' canbe of the same design as that of the element 10 in FIGS. 3 to 5.However, a suitable formation of the slots 10b and 10b" is provided forguiding the three armed spring retainer.

What I claim is:

1. A valve control mechanism for internal combustion piston engines ofthe type having a cylinder head, concentric inner and outer valves,means guiding the outer valve in the cylinder head, means guiding theinner valve in the outer valve, a common lever shaft, levers mounted onsaid shaft for operating each of a pair of said inner and outer valves,an intermediate element, said intermediate element being defined by abody having a base portion secured to the other valve and an upperportion provided with an open end, extensions projectin from the openend of the upper portion transversely with respect to the levers, areturn spring for the outer valve with one end of the spring bearingagainst the base portion of the body and the other end against thecylinder head, a retainer means secured to the inner valve, at least twoarms on said retainer means, the upper portion of the body having slotsfor receiving said arms to allow reciproca'ble movement of the arms, areturn spring for the inner valve with one end of the inner valve returnspring coacting with said arms and the other end coacting with saidcylinder head, means operably connecting one of the levers with saidinner valve for actuating the inner valve, and means operably connectingeach of said extensions with a lever for actuating the outer valvethrough said intermediate element.

2. The control mechanism as claimed in claim 1, including an actuatingstem for the outer valve, means firmly securing the base portion of theintermediate element to the actuating stem, and a rotatable joint meansbetween the base portion and the upper portion thereby allowing theactuating stem and base portion to rotate relative to the inner valve.

3. The control mechanism as claimed in claim 2, in which said jointmeans is defined by spherical surfaces on the base portion and upperportion.

4. The control mechanism as claimed in claim 1, including an actuatingstem for the outer valve, and means firmly securing the base portion ofthe intermediate element to the actuating stem.

5. The control mechanism as claimed in claim 1, in which the returnspring for the inner valve is of hair-pin form and the return spring forthe outer valve is of helical form centered on the valve axis.

6. The control mechanism as claimed in claim 1, in which the returnsprings for the inner and outer valves are of helical form centered onthe respective valve axes.

7. A valve control mechanism for internal combustion piston engines ofthe type having a cylinder head, concentric inner and outer valves,means guiding the outer valve in the cylinder head, means guiding theinner valve in the outer valve, a common lever shaft, levers mounted onsaid shaft for operating each of a pair of said inner and outer valves,a hollow actuating stem for the outer valve, an actuating stem for theinner valve mounted within the actuating stem for the outer valve, anintermediate element for each pair of inner and outer valves,

said intermediate element including a lower part and an upper parthaving an open upper end, means securing the lower part to the actuatingstem for the outer valve, spherical surfaces on the upper part and thelower part constituting a rotatable joint between such parts, extensionsprojecting horizontally from the open end of the upper part transverselywith respect to the levers, a retainer means fastly secured to theactuating stem for the H inner valve, said retainer means having threearms offset 120 relative to one another, said upper part having threevertical slots offset 120 relative to one another for receiving saidarms with the free ends of the arms extending outwardly of said upperpart, a ring carried by the free ends of said arms, a helical returnspring surrounding the actuating stem for the outer valve with one endof the spring bearing against the lower part and the other end bearingagainst the cylinder head, a helical return spring for the inner valvesurrounding the return spring for the outer valve with one end of thereturn i spring for the inner valve bearing against said ring and theother end bearing against said cylinder head, means operably connectingone of the levers with the actuating stern of the inner valve foractuating the inner valve, and means operably connecting each of saidextensions with a lever for actuating the stem of the outer valvethrough said intermediate element.

References Cited in the file of this patent UNITED STATES PATENTS1,589,441 Stenger June 22, 1956 FOREIGN PATENTS 406,424 France Dec. 8,1909 179,406 Great Britain May 11, 1922 416,496. Great Britain Sept. 17,1934

